Have you ever been trying to get your stem on, but it is just TOO tight? Refraining from sexual references, I took my solution from the Hoffman Splitter Stem. I would link to it, but they have a new one out almost every year, so I want to refrain from broken links.
They have a third bolt on their stem that threads in between the other two and pushes against it, to spread it apart (hence the name). I wanted to do this without cutting holes and threading them, etc. So I came up with this:
When you do this, don't overdo it. Parts are machined pretty close to what they need to be, I mean within .01mm, so you don't need to spread it enough to crack it. With seatclamps, I don't even use a wrench. I just use my fingers to tighten it.
be creative with what you use. You don't need a coin, you can use a washer or random piece of metal or wood laying about.